I've seen a few people around facebook asking "What's up with Blogger? Why can't I comment?" I never had that problem so didn't know anything about it. I guess it has to do with your browser. I'm on a Mac, which is why I haven't had an issue, but if you're running Internet Explorer, you might be having that problem. (which would account for the fact I've hardly had any blog comments lately!)
If you've encountered this problem, and fixed it, can you comment here with details how you fixed it? THANKS!